Please do (d) and (e) thanks QuestionA research team is working on a project to study the time (in seconds) for high school male runners to finisha 400-meter race. Jimmy, a junior researcher in the team, has randomly selected a sample of 25 male runnersfrom a high school and the time (in seconds) for each of them to complete a 400-meter race was recorded.The sample mean running time was 53 seconds. It is assumed that the running time in a 400-meter racefollows a normal distribution with a population standard deviation of 5.5 seconds.(a) Give a point estimate of the population mean running time for a 400-meter race.(b) Calculate the sampling error at 95% confidence level.(c) Construct a 95% confidence interval estimate of the population mean running time for a 400-meter race.(d) If instead of 25, 80 male runners are selected for the study, what is the sampling error at 95% confidencelevel? When the 95% confidence interval is constructed based on a sample with 80 male runners, wouldyou expect the interval will be (I) narrower, (II) wider, or (III) the same width as the confidence intervalconstructed in part (c)?(e) After discussion with the research director, Jimmy is asked to work on the research again. This time,he needs to ensure the difference between the point estimate and the true population mean be within+ 0.8 seconds at 99% confidence level.To fulfil the requirement, how large should be the minimumsample size?

It is given that Sample size n = 80 Sample mean M = 53 Population SD = 5.5 Margin of error E = 0.8…

If instead of 25, 80 male runners are selected for the study, what is the sampling error at 95% confidence level? When the 95% confidence interval is constructed based on a sample with 80 male runners, would you expect the interval will be (I) narrower, (II) wider, or (III) the same width as the confidence interval constructed in part (c)? After discussion with the research director, Jimmy is asked to work on the research again. This time, he needs to ensure the difference between the point estimate and the true population mean be within + 0.8 seconds at 99% confidence level. To fulfil the requirement, how large should be the minimum sample size?

If instead of 25, 80 male runners are selected for the study, what is the sampling error at 95% confidence level? When the 95% confidence interval is constructed based on a sample with 80 male runners, would you expect the interval will be (I) narrower, (II) wider, or (III) the same width as the confidence interval constructed in part (c)? After discussion with the research director, Jimmy is asked to work on the research again. This time, he needs to ensure the difference between the point estimate and the true population mean be within + 0.8 seconds at 99% confidence level. To fulfil the requirement, how large should be the minimum sample size?

College Algebra

10th Edition

ISBN:9781337282291

Author:Ron Larson

Publisher:Ron Larson

Chapter8: Sequences, Series,and Probability

Section8.7: Probability

Problem 50E: Flexible Work Hours In a recent survey, people were asked whether they would prefer to work flexible...

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